Nuts, bolts of who we are

Sitting in the doctor's office when he was 11
years old, Jonathan Cohen picked up a copy of
Life magazine and became engrossed in a
story about the exploding pace of neuroscience
research.

"I remember thinking 'Wow, the great frontier of
science is not out there in the stars, it's right
here with me in my head."

Three decades later, brain research is indeed a
frontier of science, and Cohen, professor of
psychology, is at the center of it. He came to
Princeton in 1998 to become director of the new
Center for the Study of Brain, Mind, and Behavior.
As its weighty name suggests, the center is an
ambitious effort to investigate some of the most
elusive and quintessentially human aspects of our
being.

The center's goal is to understand the
biological parts and processes behind such
phenomena as consciousness, moral behavior and
logical thought.

"There are more synapses in the brain than stars
in the galaxy," Cohen notes. "We are studying the
most complex device in the known universe."

Tracks converging

For many years, brain research moved along
separate tracks. Cognitive psychologists probed
behavior and experiences of the mind, while
neuroscientists investigated the physical
properties of the brain. Now advances in various
areas are allowing scientists to bring the two
tracks together. The emerging field of cognitive
neuroscience aims to reveal the physical processes
that give rise to the experiences of the mind.

"Now we're getting to the nuts and bolts of the
parts of the brain that make us who we are," says
Joshua Greene. A graduate student in philosophy, he
has begun a study to reveal biological
underpinnings of certain types of moral
behavior.

Quantitative techniques

The joint exploration of physical and mental
phenomena accelerates a trend toward using rigorous
quantitative techniques to explore areas of
psychology that were previously limited to
introspection and qualitative description, says
Cohen.

The ability to take these steps builds on
research both in and outside of psychology. The
Brain, Mind and Behavior Center has affiliated
faculty in molecular biology, applied mathematics,
engineering, computer science, physics, chemistry,
linguistics and philosophy, as well as scientists
from Rutgers University, University of Pennsylvania
and Lucent Technologies.

fMRI scanner

The single biggest technical advance driving the
center's research comes from medical science. The
center recently bought a functional magnetic
resonance imaging (fMRI) scanner, a device that
shows what portions of the brain are active during
actions and thought processes. It is the
psychologist's equivalent of a telescope turned
inward, a revolutionizing tool that allows
scientists to correlate physical processes and
mental activities with unprecedented precision.

Such machines are used frequently in diagnosing
and studying injuries and illnesses but are not
widely available to scientists doing basic
research. Although two other schools have followed
Princeton's lead, Princeton was the first
non-medical school to commit to building a human
brain-imaging center, says Cohen.

The $2 million scanner is scheduled to begin
operation this coming fall in Green Hall. It will
be twice as powerful as standard medical fMRIs,
making it among the most powerful in the country,
says Cohen.

For Greene, access to fMRI creates research
possibilities that were previously unimaginable.
His experiment, a mix of ancient and modern probes
into the human psyche, involves presenting a set of
classical ethical dilemmas to subjects who are
undergoing fMRI scans and then looking to see what
parts of the brain are engaged during moral
decisionmaking.

Greene has proposed that not all moral
decisionmaking is the same. Some moral decisions,
he argues, are produced in an "abstract" or
"cognitive" way, while others are driven by
emotional response. The scanning experiment will
compare activity in brain areas known to be
associated with logical reasoning and activity in
areas associated with emotion.

If different kinds of moral questions produce
dramatically different patterns of brain activity,
that will suggest that "the innate functional
organization of the brain, and not just the things
we've learned from experience, shapes our moral
thought in surprising ways," Greene says.

Collaboration with hospitals

In addition to yielding fundamental insights
into the brain, the center's research could shed
light on neurological and psychological illnesses.
Cohen, for example, is studying a part of the brain
that appears to monitor for conflicting situations
that vie for attention. How we direct our thoughts
in the face of conflict is a key question in
psychology, and the loss of that ability is a
defining characteristic of schizophrenia, says
Cohen.

Cohen says the center will seek to collaborate
with hospitals in New York, New Jersey and
Philadelphia. Although most of his work is basic
research, Cohen is no stranger to clinical
research. He holds an MD from the University of
Pennsylvania as well as a PhD in cognitive
psychology from Carnegie Mellon University. Before
coming to Princeton he held joint appointments at
Carnegie Mellon and the University of Pittsburgh.
He has retained his appointment at Pittsburgh and
continues to do some clinical research there.

Link with Genomics Institute

Cohen is not the only new person associated with
the center, which is participating with several
academic departments in the recruitment of faculty.
Two assistant professors with interests in
neuroscience, Michael Berry and Sam Wang, have
joined the faculty in Molecular Biology, and
assistant professors of psychology Frank Tong and
Sabine Kastner will start in the fall.

Cohen says that a long-term goal for the Brain,
Mind and Behavior Center will be to link its work
with that of the Institute for Integrative Genomics
directed by Shirley Tilghman, Howard A. Prior
Professor in the Life Sciences.

"One of the remaining great frontiers in science
is a better study of who we are," Cohen believes,
"and what that really comes down to is our genetics
and how our brain functions."

But building the connection between genes and
the mind is a slow and difficult process, one Cohen
likens to construction of the Golden Gate Bridge.
"We've started to build out from both sides and are
even building the two towers; there are boats going
back and forth right now; but the bridge is not
done."